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authorDavid Woodhouse <dwmw2@infradead.org>2008-02-03 18:29:41 +1100
committerDavid Woodhouse <dwmw2@infradead.org>2008-02-03 18:30:32 +1100
commitc1f3ee120bb61045b1c0a3ead620d1d65af47130 (patch)
tree908430bf2b47fe8e96ac623ae7ab6dd5698d0938 /kernel/module.c
parente619a75ff6201b567a539e787aa9af9bc63a3187 (diff)
parent9135f1901ee6449dfe338adf6e40e9c2025b8150 (diff)
Merge git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git
Diffstat (limited to 'kernel/module.c')
-rw-r--r--kernel/module.c294
1 files changed, 134 insertions, 160 deletions
diff --git a/kernel/module.c b/kernel/module.c
index 3202c995007..bd60278ee70 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -47,8 +47,6 @@
#include <asm/cacheflush.h>
#include <linux/license.h>
-extern int module_sysfs_initialized;
-
#if 0
#define DEBUGP printk
#else
@@ -67,6 +65,9 @@ extern int module_sysfs_initialized;
static DEFINE_MUTEX(module_mutex);
static LIST_HEAD(modules);
+/* Waiting for a module to finish initializing? */
+static DECLARE_WAIT_QUEUE_HEAD(module_wq);
+
static BLOCKING_NOTIFIER_HEAD(module_notify_list);
int register_module_notifier(struct notifier_block * nb)
@@ -81,12 +82,16 @@ int unregister_module_notifier(struct notifier_block * nb)
}
EXPORT_SYMBOL(unregister_module_notifier);
-/* We require a truly strong try_module_get() */
+/* We require a truly strong try_module_get(): 0 means failure due to
+ ongoing or failed initialization etc. */
static inline int strong_try_module_get(struct module *mod)
{
if (mod && mod->state == MODULE_STATE_COMING)
+ return -EBUSY;
+ if (try_module_get(mod))
return 0;
- return try_module_get(mod);
+ else
+ return -ENOENT;
}
static inline void add_taint_module(struct module *mod, unsigned flag)
@@ -425,6 +430,14 @@ static unsigned int find_pcpusec(Elf_Ehdr *hdr,
return find_sec(hdr, sechdrs, secstrings, ".data.percpu");
}
+static void percpu_modcopy(void *pcpudest, const void *from, unsigned long size)
+{
+ int cpu;
+
+ for_each_possible_cpu(cpu)
+ memcpy(pcpudest + per_cpu_offset(cpu), from, size);
+}
+
static int percpu_modinit(void)
{
pcpu_num_used = 2;
@@ -497,6 +510,8 @@ static struct module_attribute modinfo_##field = { \
MODINFO_ATTR(version);
MODINFO_ATTR(srcversion);
+static char last_unloaded_module[MODULE_NAME_LEN+1];
+
#ifdef CONFIG_MODULE_UNLOAD
/* Init the unload section of the module. */
static void module_unload_init(struct module *mod)
@@ -538,11 +553,21 @@ static int already_uses(struct module *a, struct module *b)
static int use_module(struct module *a, struct module *b)
{
struct module_use *use;
- int no_warn;
+ int no_warn, err;
if (b == NULL || already_uses(a, b)) return 1;
- if (!strong_try_module_get(b))
+ /* If we're interrupted or time out, we fail. */
+ if (wait_event_interruptible_timeout(
+ module_wq, (err = strong_try_module_get(b)) != -EBUSY,
+ 30 * HZ) <= 0) {
+ printk("%s: gave up waiting for init of module %s.\n",
+ a->name, b->name);
+ return 0;
+ }
+
+ /* If strong_try_module_get() returned a different error, we fail. */
+ if (err)
return 0;
DEBUGP("Allocating new usage for %s.\n", a->name);
@@ -720,6 +745,8 @@ sys_delete_module(const char __user *name_user, unsigned int flags)
mod->exit();
mutex_lock(&module_mutex);
}
+ /* Store the name of the last unloaded module for diagnostic purposes */
+ strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
free_module(mod);
out:
@@ -813,7 +840,7 @@ static inline void module_unload_free(struct module *mod)
static inline int use_module(struct module *a, struct module *b)
{
- return strong_try_module_get(b);
+ return strong_try_module_get(b) == 0;
}
static inline void module_unload_init(struct module *mod)
@@ -952,7 +979,8 @@ static unsigned long resolve_symbol(Elf_Shdr *sechdrs,
ret = __find_symbol(name, &owner, &crc,
!(mod->taints & TAINT_PROPRIETARY_MODULE));
if (ret) {
- /* use_module can fail due to OOM, or module unloading */
+ /* use_module can fail due to OOM,
+ or module initialization or unloading */
if (!check_version(sechdrs, versindex, name, mod, crc) ||
!use_module(mod, owner))
ret = 0;
@@ -1120,7 +1148,7 @@ static void add_notes_attrs(struct module *mod, unsigned int nsect,
++loaded;
}
- notes_attrs->dir = kobject_add_dir(&mod->mkobj.kobj, "notes");
+ notes_attrs->dir = kobject_create_and_add("notes", &mod->mkobj.kobj);
if (!notes_attrs->dir)
goto out;
@@ -1210,6 +1238,7 @@ void module_remove_modinfo_attrs(struct module *mod)
int mod_sysfs_init(struct module *mod)
{
int err;
+ struct kobject *kobj;
if (!module_sysfs_initialized) {
printk(KERN_ERR "%s: module sysfs not initialized\n",
@@ -1217,15 +1246,25 @@ int mod_sysfs_init(struct module *mod)
err = -EINVAL;
goto out;
}
- memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
- err = kobject_set_name(&mod->mkobj.kobj, "%s", mod->name);
- if (err)
+
+ kobj = kset_find_obj(module_kset, mod->name);
+ if (kobj) {
+ printk(KERN_ERR "%s: module is already loaded\n", mod->name);
+ kobject_put(kobj);
+ err = -EINVAL;
goto out;
- kobj_set_kset_s(&mod->mkobj, module_subsys);
+ }
+
mod->mkobj.mod = mod;
- kobject_init(&mod->mkobj.kobj);
+ memset(&mod->mkobj.kobj, 0, sizeof(mod->mkobj.kobj));
+ mod->mkobj.kobj.kset = module_kset;
+ err = kobject_init_and_add(&mod->mkobj.kobj, &module_ktype, NULL,
+ "%s", mod->name);
+ if (err)
+ kobject_put(&mod->mkobj.kobj);
+ /* delay uevent until full sysfs population */
out:
return err;
}
@@ -1236,12 +1275,7 @@ int mod_sysfs_setup(struct module *mod,
{
int err;
- /* delay uevent until full sysfs population */
- err = kobject_add(&mod->mkobj.kobj);
- if (err)
- goto out;
-
- mod->holders_dir = kobject_add_dir(&mod->mkobj.kobj, "holders");
+ mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
if (!mod->holders_dir) {
err = -ENOMEM;
goto out_unreg;
@@ -1261,11 +1295,9 @@ int mod_sysfs_setup(struct module *mod,
out_unreg_param:
module_param_sysfs_remove(mod);
out_unreg_holders:
- kobject_unregister(mod->holders_dir);
+ kobject_put(mod->holders_dir);
out_unreg:
- kobject_del(&mod->mkobj.kobj);
kobject_put(&mod->mkobj.kobj);
-out:
return err;
}
#endif
@@ -1274,9 +1306,20 @@ static void mod_kobject_remove(struct module *mod)
{
module_remove_modinfo_attrs(mod);
module_param_sysfs_remove(mod);
- kobject_unregister(mod->mkobj.drivers_dir);
- kobject_unregister(mod->holders_dir);
- kobject_unregister(&mod->mkobj.kobj);
+ kobject_put(mod->mkobj.drivers_dir);
+ kobject_put(mod->holders_dir);
+ kobject_put(&mod->mkobj.kobj);
+}
+
+/*
+ * link the module with the whole machine is stopped with interrupts off
+ * - this defends against kallsyms not taking locks
+ */
+static int __link_module(void *_mod)
+{
+ struct module *mod = _mod;
+ list_add(&mod->list, &modules);
+ return 0;
}
/*
@@ -1328,7 +1371,7 @@ void *__symbol_get(const char *symbol)
preempt_disable();
value = __find_symbol(symbol, &owner, &crc, 1);
- if (value && !strong_try_module_get(owner))
+ if (value && strong_try_module_get(owner) != 0)
value = 0;
preempt_enable();
@@ -1369,7 +1412,7 @@ dup:
return ret;
}
-/* Change all symbols so that sh_value encodes the pointer directly. */
+/* Change all symbols so that st_value encodes the pointer directly. */
static int simplify_symbols(Elf_Shdr *sechdrs,
unsigned int symindex,
const char *strtab,
@@ -1882,16 +1925,16 @@ static struct module *load_module(void __user *umod,
/* Now we've moved module, initialize linked lists, etc. */
module_unload_init(mod);
- /* Initialize kobject, so we can reference it. */
+ /* add kobject, so we can reference it. */
err = mod_sysfs_init(mod);
if (err)
- goto cleanup;
+ goto free_unload;
/* Set up license info based on the info section */
set_license(mod, get_modinfo(sechdrs, infoindex, "license"));
if (strcmp(mod->name, "ndiswrapper") == 0)
- add_taint(TAINT_PROPRIETARY_MODULE);
+ add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
if (strcmp(mod->name, "driverloader") == 0)
add_taint_module(mod, TAINT_PROPRIETARY_MODULE);
@@ -2021,6 +2064,11 @@ static struct module *load_module(void __user *umod,
printk(KERN_WARNING "%s: Ignoring obsolete parameters\n",
mod->name);
+ /* Now sew it into the lists so we can get lockdep and oops
+ * info during argument parsing. Noone should access us, since
+ * strong_try_module_get() will fail. */
+ stop_machine_run(__link_module, mod, NR_CPUS);
+
/* Size of section 0 is 0, so this works well if no params */
err = parse_args(mod->name, mod->args,
(struct kernel_param *)
@@ -2029,7 +2077,7 @@ static struct module *load_module(void __user *umod,
/ sizeof(struct kernel_param),
NULL);
if (err < 0)
- goto arch_cleanup;
+ goto unlink;
err = mod_sysfs_setup(mod,
(struct kernel_param *)
@@ -2037,7 +2085,7 @@ static struct module *load_module(void __user *umod,
sechdrs[setupindex].sh_size
/ sizeof(struct kernel_param));
if (err < 0)
- goto arch_cleanup;
+ goto unlink;
add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
@@ -2052,9 +2100,13 @@ static struct module *load_module(void __user *umod,
/* Done! */
return mod;
- arch_cleanup:
+ unlink:
+ stop_machine_run(__unlink_module, mod, NR_CPUS);
module_arch_cleanup(mod);
cleanup:
+ kobject_del(&mod->mkobj.kobj);
+ kobject_put(&mod->mkobj.kobj);
+ free_unload:
module_unload_free(mod);
module_free(mod, mod->module_init);
free_core:
@@ -2074,17 +2126,6 @@ static struct module *load_module(void __user *umod,
goto free_hdr;
}
-/*
- * link the module with the whole machine is stopped with interrupts off
- * - this defends against kallsyms not taking locks
- */
-static int __link_module(void *_mod)
-{
- struct module *mod = _mod;
- list_add(&mod->list, &modules);
- return 0;
-}
-
/* This is where the real work happens */
asmlinkage long
sys_init_module(void __user *umod,
@@ -2109,10 +2150,6 @@ sys_init_module(void __user *umod,
return PTR_ERR(mod);
}
- /* Now sew it into the lists. They won't access us, since
- strong_try_module_get() will fail. */
- stop_machine_run(__link_module, mod, NR_CPUS);
-
/* Drop lock so they can recurse */
mutex_unlock(&module_mutex);
@@ -2131,6 +2168,7 @@ sys_init_module(void __user *umod,
mutex_lock(&module_mutex);
free_module(mod);
mutex_unlock(&module_mutex);
+ wake_up(&module_wq);
return ret;
}
@@ -2145,6 +2183,7 @@ sys_init_module(void __user *umod,
mod->init_size = 0;
mod->init_text_size = 0;
mutex_unlock(&module_mutex);
+ wake_up(&module_wq);
return 0;
}
@@ -2209,32 +2248,41 @@ static const char *get_ksymbol(struct module *mod,
return mod->strtab + mod->symtab[best].st_name;
}
-/* For kallsyms to ask for address resolution. NULL means not found.
- We don't lock, as this is used for oops resolution and races are a
- lesser concern. */
-const char *module_address_lookup(unsigned long addr,
- unsigned long *size,
- unsigned long *offset,
- char **modname)
+/* For kallsyms to ask for address resolution. NULL means not found. Careful
+ * not to lock to avoid deadlock on oopses, simply disable preemption. */
+char *module_address_lookup(unsigned long addr,
+ unsigned long *size,
+ unsigned long *offset,
+ char **modname,
+ char *namebuf)
{
struct module *mod;
+ const char *ret = NULL;
+ preempt_disable();
list_for_each_entry(mod, &modules, list) {
if (within(addr, mod->module_init, mod->init_size)
|| within(addr, mod->module_core, mod->core_size)) {
if (modname)
*modname = mod->name;
- return get_ksymbol(mod, addr, size, offset);
+ ret = get_ksymbol(mod, addr, size, offset);
+ break;
}
}
- return NULL;
+ /* Make a copy in here where it's safe */
+ if (ret) {
+ strncpy(namebuf, ret, KSYM_NAME_LEN - 1);
+ ret = namebuf;
+ }
+ preempt_enable();
+ return (char *)ret;
}
int lookup_module_symbol_name(unsigned long addr, char *symname)
{
struct module *mod;
- mutex_lock(&module_mutex);
+ preempt_disable();
list_for_each_entry(mod, &modules, list) {
if (within(addr, mod->module_init, mod->init_size) ||
within(addr, mod->module_core, mod->core_size)) {
@@ -2244,12 +2292,12 @@ int lookup_module_symbol_name(unsigned long addr, char *symname)
if (!sym)
goto out;
strlcpy(symname, sym, KSYM_NAME_LEN);
- mutex_unlock(&module_mutex);
+ preempt_enable();
return 0;
}
}
out:
- mutex_unlock(&module_mutex);
+ preempt_enable();
return -ERANGE;
}
@@ -2258,7 +2306,7 @@ int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
{
struct module *mod;
- mutex_lock(&module_mutex);
+ preempt_disable();
list_for_each_entry(mod, &modules, list) {
if (within(addr, mod->module_init, mod->init_size) ||
within(addr, mod->module_core, mod->core_size)) {
@@ -2271,12 +2319,12 @@ int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size,
strlcpy(modname, mod->name, MODULE_NAME_LEN);
if (name)
strlcpy(name, sym, KSYM_NAME_LEN);
- mutex_unlock(&module_mutex);
+ preempt_enable();
return 0;
}
}
out:
- mutex_unlock(&module_mutex);
+ preempt_enable();
return -ERANGE;
}
@@ -2285,7 +2333,7 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
{
struct module *mod;
- mutex_lock(&module_mutex);
+ preempt_disable();
list_for_each_entry(mod, &modules, list) {
if (symnum < mod->num_symtab) {
*value = mod->symtab[symnum].st_value;
@@ -2294,12 +2342,12 @@ int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
KSYM_NAME_LEN);
strlcpy(module_name, mod->name, MODULE_NAME_LEN);
*exported = is_exported(name, mod);
- mutex_unlock(&module_mutex);
+ preempt_enable();
return 0;
}
symnum -= mod->num_symtab;
}
- mutex_unlock(&module_mutex);
+ preempt_enable();
return -ERANGE;
}
@@ -2322,6 +2370,7 @@ unsigned long module_kallsyms_lookup_name(const char *name)
unsigned long ret = 0;
/* Don't lock: we're in enough trouble already. */
+ preempt_disable();
if ((colon = strchr(name, ':')) != NULL) {
*colon = '\0';
if ((mod = find_module(name)) != NULL)
@@ -2332,6 +2381,7 @@ unsigned long module_kallsyms_lookup_name(const char *name)
if ((ret = mod_find_symname(mod, name)) != 0)
break;
}
+ preempt_enable();
return ret;
}
#endif /* CONFIG_KALLSYMS */
@@ -2353,21 +2403,30 @@ static void m_stop(struct seq_file *m, void *p)
mutex_unlock(&module_mutex);
}
-static char *taint_flags(unsigned int taints, char *buf)
+static char *module_flags(struct module *mod, char *buf)
{
int bx = 0;
- if (taints) {
+ if (mod->taints ||
+ mod->state == MODULE_STATE_GOING ||
+ mod->state == MODULE_STATE_COMING) {
buf[bx++] = '(';
- if (taints & TAINT_PROPRIETARY_MODULE)
+ if (mod->taints & TAINT_PROPRIETARY_MODULE)
buf[bx++] = 'P';
- if (taints & TAINT_FORCED_MODULE)
+ if (mod->taints & TAINT_FORCED_MODULE)
buf[bx++] = 'F';
/*
* TAINT_FORCED_RMMOD: could be added.
* TAINT_UNSAFE_SMP, TAINT_MACHINE_CHECK, TAINT_BAD_PAGE don't
* apply to modules.
*/
+
+ /* Show a - for module-is-being-unloaded */
+ if (mod->state == MODULE_STATE_GOING)
+ buf[bx++] = '-';
+ /* Show a + for module-is-being-loaded */
+ if (mod->state == MODULE_STATE_COMING)
+ buf[bx++] = '+';
buf[bx++] = ')';
}
buf[bx] = '\0';
@@ -2394,7 +2453,7 @@ static int m_show(struct seq_file *m, void *p)
/* Taints info */
if (mod->taints)
- seq_printf(m, " %s", taint_flags(mod->taints, buf));
+ seq_printf(m, " %s", module_flags(mod, buf));
seq_printf(m, "\n");
return 0;
@@ -2489,97 +2548,12 @@ void print_modules(void)
printk("Modules linked in:");
list_for_each_entry(mod, &modules, list)
- printk(" %s%s", mod->name, taint_flags(mod->taints, buf));
+ printk(" %s%s", mod->name, module_flags(mod, buf));
+ if (last_unloaded_module[0])
+ printk(" [last unloaded: %s]", last_unloaded_module);
printk("\n");
}
-#ifdef CONFIG_SYSFS
-static char *make_driver_name(struct device_driver *drv)
-{
- char *driver_name;
-
- driver_name = kmalloc(strlen(drv->name) + strlen(drv->bus->name) + 2,
- GFP_KERNEL);
- if (!driver_name)
- return NULL;
-
- sprintf(driver_name, "%s:%s", drv->bus->name, drv->name);
- return driver_name;
-}
-
-static void module_create_drivers_dir(struct module_kobject *mk)
-{
- if (!mk || mk->drivers_dir)
- return;
-
- mk->drivers_dir = kobject_add_dir(&mk->kobj, "drivers");
-}
-
-void module_add_driver(struct module *mod, struct device_driver *drv)
-{
- char *driver_name;
- int no_warn;
- struct module_kobject *mk = NULL;
-
- if (!drv)
- return;
-
- if (mod)
- mk = &mod->mkobj;
- else if (drv->mod_name) {
- struct kobject *mkobj;
-
- /* Lookup built-in module entry in /sys/modules */
- mkobj = kset_find_obj(&module_subsys, drv->mod_name);
- if (mkobj) {
- mk = container_of(mkobj, struct module_kobject, kobj);
- /* remember our module structure */
- drv->mkobj = mk;
- /* kset_find_obj took a reference */
- kobject_put(mkobj);
- }
- }
-
- if (!mk)
- return;
-
- /* Don't check return codes; these calls are idempotent */
- no_warn = sysfs_create_link(&drv->kobj, &mk->kobj, "module");
- driver_name = make_driver_name(drv);
- if (driver_name) {
- module_create_drivers_dir(mk);
- no_warn = sysfs_create_link(mk->drivers_dir, &drv->kobj,
- driver_name);
- kfree(driver_name);
- }
-}
-EXPORT_SYMBOL(module_add_driver);
-
-void module_remove_driver(struct device_driver *drv)
-{
- struct module_kobject *mk = NULL;
- char *driver_name;
-
- if (!drv)
- return;
-
- sysfs_remove_link(&drv->kobj, "module");
-
- if (drv->owner)
- mk = &drv->owner->mkobj;
- else if (drv->mkobj)
- mk = drv->mkobj;
- if (mk && mk->drivers_dir) {
- driver_name = make_driver_name(drv);
- if (driver_name) {
- sysfs_remove_link(mk->drivers_dir, driver_name);
- kfree(driver_name);
- }
- }
-}
-EXPORT_SYMBOL(module_remove_driver);
-#endif
-
#ifdef CONFIG_MODVERSIONS
/* Generate the signature for struct module here, too, for modversions. */
void struct_module(struct module *mod) { return; }